The present invention discloses processes for producing -dicarbonyl compounds by contacting an aldehyde compound, an ,-unsaturated carbonyl compound, and a catalyst composition in the presence of an amide diluent. The resultant -dicarbonyl compounds then can be used to synthesize pyrrole compounds, such as 2,5-dimethylpyrrole.

A synthesis method of 3,4-hexanedione comprises a step of 4-hydroxy-3-hexanonen oxidation, and in the step of 4-hydroxy-3-hexanonen oxidation, water is used as a catalyst, acetic acid is used as a cocatalyst, and ozone is used as an oxidizing agent to carry out an oxidation reaction on 4-hydroxy-3-hexanonen, and after the reaction, distillation under reduced pressure is carried out to obtain the 3,4-hexanedione. According to the synthesis method of 3,4-hexanedione in the invention, in the process of 4-hydroxy-3-hexanone oxidation, the 4-hydroxy-3-hexanone is placed in the water, the ozone is used for oxidation on the 4-hydroxy-3-hexanone, and the acetic acid is used as the cocatalyst, so that the entire oxidation reaction process is mild in conditions and simple to operate, no sewage is produced when the final product (3,4-hexanedione) is obtained, and the yield is greatly increased.

A synthesis method of 3,4-hexanedione comprises a step of 4-hydroxy-3-hexanonen oxidation, and in the step of 4-hydroxy-3-hexanonen oxidation, water is used as a catalyst, acetic acid is used as a cocatalyst, and ozone is used as an oxidizing agent to carry out an oxidation reaction on 4-hydroxy-3-hexanonen, and after the reaction, distillation under reduced pressure is carried out to obtain the 3,4-hexanedione. According to the synthesis method of 3,4-hexanedione in the invention, in the process of 4-hydroxy-3-hexanone oxidation, the 4-hydroxy-3-hexanone is placed in the water, the ozone is used for oxidation on the 4-hydroxy-3-hexanone, and the acetic acid is used as the cocatalyst, so that the entire oxidation reaction process is mild in conditions and simple to operate, no sewage is produced when the final product (3,4-hexanedione) is obtained, and the yield is greatly increased.

A synthesis method of 3,4-hexanedione comprises a step of 4-hydroxy-3-hexanonen oxidation, and in the step of 4-hydroxy-3-hexanonen oxidation, water is used as a catalyst, acetic acid is used as a cocatalyst, and ozone is used as an oxidizing agent to carry out an oxidation reaction on 4-hydroxy-3-hexanonen, and after the reaction, distillation under reduced pressure is carried out to obtain the 3,4-hexanedione. According to the synthesis method of 3,4-hexanedione in the invention, in the process of 4-hydroxy-3-hexanone oxidation, the 4-hydroxy-3-hexanone is placed in the water, the ozone is used for oxidation on the 4-hydroxy-3-hexanone, and the acetic acid is used as the cocatalyst, so that the entire oxidation reaction process is mild in conditions and simple to operate, no sewage is produced when the final product (3,4-hexanedione) is obtained, and the yield is greatly increased.

A biphasic solvent system for converting biomass to prepare 2,5-hexanedione and a one-pot process for catalytically converting biomass to prepare 2,5-hexanedione with said biphasic solvent system are provided. The process includes the steps of contacting and reacting a biomass raw material with a hydrogenation catalyst using hydrogen gas as a hydrogen source in a heterogeneous system formed from an organic solvent, an inorganic salt and water to obtain 2,5-hexanedione. The hydrogenation catalyst includes a hydrogenation active component and a support. The support is selected from one or more of hydrophobic active carbon and graphene. The process can achieve efficient conversion of biomass without the participation of acid catalysts, and have a very high selectivity for the product 2,5-hexanedione.

A biphasic solvent system for converting biomass to prepare 2,5-hexanedione and a one-pot process for catalytically converting biomass to prepare 2,5-hexanedione with said biphasic solvent system are provided. The process includes the steps of contacting and reacting a biomass raw material with a hydrogenation catalyst using hydrogen gas as a hydrogen source in a heterogeneous system formed from an organic solvent, an inorganic salt and water to obtain 2,5-hexanedione. The hydrogenation catalyst includes a hydrogenation active component and a support. The support is selected from one or more of hydrophobic active carbon and graphene. The process can achieve efficient conversion of biomass without the participation of acid catalysts, and have a very high selectivity for the product 2,5-hexanedione.

A synthesis method of 3,4-hexanedione comprises a step of 4-hydroxy-3-hexanonen oxidation, and in the step of 4-hydroxy-3-hexanonen oxidation, water is used as a catalyst, acetic acid is used as a cocatalyst, and ozone is used as an oxidizing agent to carry out an oxidation reaction on 4-hydroxy-3-hexanonen, and after the reaction, distillation under reduced pressure is carried out to obtain the 3,4-hexanedione. According to the synthesis method of 3,4-hexanedione in the invention, in the process of 4-hydroxy-3-hexanone oxidation, the 4-hydroxy-3-hexanone is placed in the water, the ozone is used for oxidation on the 4-hydroxy-3-hexanone, and the acetic acid is used as the cocatalyst, so that the entire oxidation reaction process is mild in conditions and simple to operate, no sewage is produced when the final product (3,4-hexanedione) is obtained, and the yield is greatly increased.

A synthesis method of 3,4-hexanedione comprises a step of 4-hydroxy-3-hexanonen oxidation, and in the step of 4-hydroxy-3-hexanonen oxidation, water is used as a catalyst, acetic acid is used as a cocatalyst, and ozone is used as an oxidizing agent to carry out an oxidation reaction on 4-hydroxy-3-hexanonen, and after the reaction, distillation under reduced pressure is carried out to obtain the 3,4-hexanedione. According to the synthesis method of 3,4-hexanedione in the invention, in the process of 4-hydroxy-3-hexanone oxidation, the 4-hydroxy-3-hexanone is placed in the water, the ozone is used for oxidation on the 4-hydroxy-3-hexanone, and the acetic acid is used as the cocatalyst, so that the entire oxidation reaction process is mild in conditions and simple to operate, no sewage is produced when the final product (3,4-hexanedione) is obtained, and the yield is greatly increased.

A synthesis method of 3,4-hexanedione comprises a step of 4-hydroxy-3-hexanonen oxidation, and in the step of 4-hydroxy-3-hexanonen oxidation, water is used as a catalyst, acetic acid is used as a cocatalyst, and ozone is used as an oxidizing agent to carry out an oxidation reaction on 4-hydroxy-3-hexanonen, and after the reaction, distillation under reduced pressure is carried out to obtain the 3,4-hexanedione. According to the synthesis method of 3,4-hexanedione in the invention, in the process of 4-hydroxy-3-hexanone oxidation, the 4-hydroxy-3-hexanone is placed in the water, the ozone is used for oxidation on the 4-hydroxy-3-hexanone, and the acetic acid is used as the cocatalyst, so that the entire oxidation reaction process is mild in conditions and simple to operate, no sewage is produced when the final product (3,4-hexanedione) is obtained, and the yield is greatly increased.

Disclosed is a process for preparing a product of formula I: wherein the reaction is catalyzed both by thiamine or a thiamine salt and by ascorbic acid in a form which is free or salified or an organic acid salt of an alkaline metal, preferably sodium acetate, potassium tartrate, sodium succinate, or a reductone, preferably 2-hydroxypropanedial or 2,3-dihydroxycyclopent-2-ene-1-one in an organic solvent.